What Makes A Water Injection Nozzle Better Than Others?

Posted by Rachel Farabaugh on October 09, 2015

One of the most important parts of a water methanol injection system is the water injection nozzle. It is the last part of the water injection system which the fluid passes through before entering into the engines air intake system. It is this part whose job is to both regulate the amount of fluid being sprayed into the engine while also atomizing it, breaking the fluid up, into tiny more usable droplets.

What makes a water injection nozzle truly better than other nozzles is how well the nozzle atomizes the fluid and delivers it into the air charge of an engine. That is the key to a better nozzle. This is what determines if a nozzle is better than another nozzle. Not by spraying the nozzle into the open air and judging how the nozzle looks and feels 1-2 feet away from the nozzle. The point of interests and what people should be looking at is what happens within the first half inch after the orifice of the nozzle. We will discuss and explain more about this in just a bit.

Benefits Of Better Atomization Include The Following:

Smaller lighter droplets stay suspended in air charge better keeping more of the mixture in the air charge vs heavier droplets which are more likely to fall out of suspension

Smaller lighter droplets are carried better with the air charge for improved more equal distribution throughout the intake manifold

Reduces "puddling" effect and fluid dragging along the intakes floor

Improved cooling effect on forced induction applications due to greater number of droplets resulting in increased surface area of mixture for better absorption

Mixes better with air fuel for improved combustion

Overall improved function of the water methanol injection system

How Air Speed Effects Spray Pattern

Before we can talk about water injection nozzles we first need to understand the conditions it's working within. Most applications we work with are supercharged or turbocharged engines where the nozzles are commonly mounted in either the air charge pipe, carburetor hat or intake manifold. The air moving through these ports is traveling at an extremely fast rate and can reach speeds over 600 ft. per second equal to 400+ mph. We all know what it feels like holding our hand out the car window while doing 50-60 mph. Now imagine the force you would feel at speeds over 400 mph.

When a nozzle is mounted in these locations. The tip of the nozzle is usually exposed, as seen in the picture here, and extends out into the air charge. With the extreme speed the air charge is moving. The high speed air charge virtually shears the injection shortly after exiting the orifice of the nozzle. Preventing the injection from fanning out into the air stream reducing the nozzles atomization. Nozzles do not spray across the port as commonly believed.

So What Makes Our Water Injection Nozzles Better?

The one feature that separates our nozzle from other water injection nozzles on the market is the chamber machined into the tip of the nozzle. This is the single most significant feature that separates our nozzle from other nozzles in the industry. Without an explanation most people overlook and do not understand the significance of this feature and how it helps the nozzle spray and improve atomization. Follow along as we explain.

All AIS nozzles come with a chamber at the tip of the nozzle which the orifice, hole which fluid exits from, is recessed within. The chamber is .120" deep with an inside diameter of .280" wide. All nozzles have an 80 degree hollow cone spray pattern. By having the orifice recessed within the chamber. It shrouds the orifice shielding it from the high speed air charge passing over it. Allowing the injection time to fan out and atomize before entering the air charge.

Depending on the size of the nozzle being used. The injection spray pattern is now 5-7 times wider at the point of entry into the air stream vs the competitors nozzles non-recessed nozzles whose point of entry for the fluid being sprayed is immediately after it exits the orifice of the nozzle. The result is a much wider and finer spray pattern entering into the air charge compared to the competitors narrower less atomized spray pattern.

Below is an image that's been photo shopped demonstrating the difference in the injection spray pattern between a non-recessed nozzle (top view) and that same nozzle had the orifice been recessed (bottom view). Notice on the top view how narrow the injection spray pattern would be if it were entering into a high speed air charge. Additionally, the fluid is still laced together at the start of the spray pattern. As the injection spray pattern widens the fluid begins to separate forming smaller droplets. Compare this to the bottom nozzle with recessed tip. You have a much wider spray pattern entering into the air charge. Additionally, the spray pattern has begun to separate into smaller droplets resulting in better atomization.